pfconfig(8c)
Name
pfconfig − configure packet filter parameters
Syntax
/usr/etc/pfconfig [ +/−p[romisc] ] [ −b[acklog] nnn ] [ −a[ll] ] [interface-name ...]
Description
The pfconfig command allows the system manager to configure certain parameters of the packet filter driver (see packetfilter(4)). These parameters are configured separately for each interface; the interfaces are specified by name on the command line (for example, ln0, and ni1). If more than one interface is specified, they are all given the same settings. Alternatively, you can specify to configure all the packet-filter interfaces on the system.
You can set the following parameters with pfconfig:
+promiscAllows packet filter users to set the interface into promiscuous mode (receives all packets). Whenever there is at least one packet filter descriptor open with the ENPROMISC mode bit set, the interface will be in promiscuous mode. When no such descriptors are in use, the interface will be returned to normal mode.
−promiscThe interface will no longer be put into promiscuous mode on behalf of packet filter users; if the interface is in promiscuous mode when this command is given, it is returned to normal mode. (The superuser may use ifconfig(8c) to control promiscuous mode, overiding the mode set by non-superusers. This is the default setting.)
−backlog nnn
Sets the maximum backlog (packet filter input queue length) for non-superuser descriptors to the specified number. When a descriptor is opened, it is given a queue length limit of two. An application can increase this backlog using the EIOCSETW ioctl request. Superusers are allowed to increase their backlog up to a system-wide maximum; non-superusers are allowed to increase their backlog only up to the maximum set by this program. Note that allowing too large a backlog may result in vast amounts of kernel memory being tied up in the packet filter driver queues.
If no configuration parameters are specified, the pfconfig command displays the current packet filter configuration for the network interface(s).
Only the superuser may use this command to change the configuration.
Examples
On a system used for network monitoring, one might put this line into /etc/rc.local:
/usr/etc/pfconfig −a +promisc −backlog 64
This allows users to run promiscuous network monitoring applications, with a maximum input queue length per application of 64 packets, on any interface in the system.
Diagnostics
Messages indicating the specified interface do not exist; an attempt to set a maximum backlog less than 1 or greater than the system-wide maximum; the user tried to alter an interface’s configuration but is not privileged.